Carbon-Based Enzyme Mimetics for Electrochemical Biosensing.

Natural enzymes are used as special reagents for the preparation of electrochemical (bio)sensors due to their ability to catalyze processes, improving the selectivity of detection. However, some drawbacks, such as denaturation in harsh experimental conditions and their rapid de- gradation, as well as the high cost and difficulties in recycling them, restrict their practical applications. Nowadays, the use of artificial enzymes, mostly based on nanomaterials, mimicking the functions of natural products, has been growing.

p53 and p63 Proteoforms Derived from Alternative Splicing Possess Differential Seroreactivity in Colorectal Cancer with Distinct Diagnostic Ability from the Canonical Proteins.

Colorectal cancer (CRC) is the third most common cancer and the second most frequent cause of cancer-related death worldwide. The detection in plasma samples of autoantibodies against specific tumor-associated antigens has been demonstrated to be useful for the early diagnosis of CRC by liquid biopsy. However, new studies related to the humoral immune response in cancer are needed to enable blood-based diagnosis of the disease.

Electrochemical (Bio)Sensing Devices for Human-Microbiome-Related Biomarkers.

The study of the human microbiome is a multidisciplinary area ranging from the field of technology to that of personalized medicine. The possibility of using microbiota biomarkers to improve the diagnosis and monitoring of diseases (e.g.

Revisiting Electrochemical Biosensing in the 21st Century Society for Inflammatory Cytokines Involved in Autoimmune, Neurodegenerative, Cardiac, Viral and Cancer Diseases.

The multifaceted key roles of cytokines in immunity and inflammatory processes have led to a high clinical interest for the determination of these biomolecules to be used as a tool in the diagnosis, prognosis, monitoring and treatment of several diseases of great current relevance (autoimmune, neurodegenerative, cardiac, viral and cancer diseases, hypercholesterolemia and diabetes). Therefore, the rapid and accurate determination of cytokine biomarkers in body fluids, cells and tissues has attracted considerable attention. However, many currently available techniques used for this purpose, although sensitive and selective, require expensive equipment and advanced human skills and do not meet the demands of today's clinic in terms of test time, simplicity and point-of-care applicability.

Multimodal/Multifunctional Nanomaterials in (Bio)electrochemistry: Now and in the Coming Decade.

Multifunctional nanomaterials, defined as those able to achieve a combined effect or more than one function through their multiple functionalization or combination with other materials, are gaining increasing attention in the last years in many relevant fields, including cargo targeted delivery, tissue engineering, in vitro and/or in vivo diseases imaging and therapy, as well as in the development of electrochemical (bio)sensors and (bio)sensing strategies with improved performance. This review article aims to provide an updated overview of the important advances and future opportunities exhibited by electrochemical biosensing in connection to multifunctional nanomaterials. Accordingly, representative aspects of recent approaches involving metal, carbon, and silica-based multifunctional nanomaterials are selected and critically discussed, as they are the most widely used multifunctional nanomaterials imparting unique capabilities in (bio)electroanalysis.

Screen-Printed Electrodes: Promising Paper and Wearable Transducers for (Bio)Sensing.

Screen-printing technology has revolutionized many fields, including that of electrochemical biosensing. Due to their current relevance, this review, unlike other papers, discusses the relevant aspects of electrochemical biosensors manufactured using this technology in connection to both paper substrates and wearable formats. The main trends, advances, and opportunities provided by these types of devices, with particular attention to the environmental and biomedical fields, are addressed along with illustrative fundamentals and applications of selected representative approaches from the recent literature.

Beyond Sensitive and Selective Electrochemical Biosensors: Towards Continuous, Real-Time, Antibiofouling and Calibration-Free Devices.

Nowadays, electrochemical biosensors are reliable analytical tools to determine a broad range of molecular analytes because of their simplicity, affordable cost, and compatibility with multiplexed and point-of-care strategies. There is an increasing demand to improve their sensitivity and selectivity, but also to provide electrochemical biosensors with important attributes such as near real-time and continuous monitoring in complex or denaturing media, or in vivo with minimal intervention to make them even more attractive and suitable for getting into the real world. Modification of biosensors surfaces with antibiofouling reagents, smart coupling with nanomaterials, and the advances experienced by folded-based biosensors have endowed bioelectroanalytical platforms with one or more of such attributes.

Multiplexed monitoring of a novel autoantibody diagnostic signature of colorectal cancer using HaloTag technology-based electrochemical immunosensing platform.

: The humoral immune response in cancer patients can be used for early detection of the disease. Autoantibodies raised against tumor-associated antigens (TAAs) are promising clinical biomarkers for reliable cancer diagnosis, prognosis, and therapy monitoring. In this study, an electrochemical disposable multiplexed immunosensing platform able to integrate difficult- and easy-to-express colorectal cancer (CRC) TAAs is reported for the sensitive determination of eight CRC-specific autoantibodies.

Cutting-Edge Advances in Electrochemical Affinity Biosensing at Different Molecular Level of Emerging Food Allergens and Adulterants.

The presence of allergens and adulterants in food, which represents a real threat to sensitized people and a loss of consumer confidence, is one of the main current problems facing society. The detection of allergens and adulterants in food, mainly at the genetic level (characteristic fragments of genes that encode their expression) or at functional level (protein biomarkers) is a complex task due to the natural interference of the matrix and the low concentration at which they are present. Methods for the analysis of allergens are mainly divided into immunological and deoxyribonucleic acid (DNA)-based assays.

Biosensing and Delivery of Nucleic Acids Involving Selected Well-Known and Rising Star Functional Nanomaterials.

In the last fifteen years, the nucleic acid biosensors and delivery area has seen a breakthrough due to the interrelation between the recognition of nucleic acid's high specificity, the great sensitivity of electrochemical and optical transduction and the unprecedented opportunities imparted by nanotechnology. Advances in this area have demonstrated that the assembly of nanoscaled materials allows the performance enhancement, particularly in terms of sensitivity and response time, of functional nucleic acids' biosensing and delivery to a level suitable for the construction of point-of-care diagnostic tools. Consequently, this has propelled detection methods using nanomaterials to the vanguard of the biosensing and delivery research fields.

What Electrochemical Biosensors Can Do for Forensic Science? Unique Features and Applications.

This article critically discusses the latest advances in the use of voltammetric, amperometric, potentiometric, and impedimetric biosensors for forensic analysis. Highlighted examples that show the advantages of these tools to develop methods capable of detecting very small concentrations of analytes and provide selective determinations through analytical responses, without significant interferences from other components of the samples, are presented and discussed, thus stressing the great versatility and utility of electrochemical biosensors in this growing research field. To illustrate this, the determination of substances with forensic relevance by using electrochemical biosensors reported in the last five years (2015-2019) are reviewed.

11PS04 is a new chemical entity identified by microRNA-based biosensing with promising therapeutic potential against cancer stem cells.

Phenotypic drug discovery must take advantage of the large amount of clinical data currently available. In this sense, the impact of microRNAs (miRs) on human disease and clinical therapeutic responses is becoming increasingly well documented. Accordingly, it might be possible to use miR-based signatures as phenotypic read-outs of pathological status, for example in cancer.

Hybrid Decorated Core@Shell Janus Nanoparticles as a Flexible Platform for Targeted Multimodal Molecular Bioimaging of Cancer.

In the recent years, targeted cancer theranosis, the concomitant therapeutic treatment and selective visualization of cancerous tissue, has become a powerful strategy to improve patient prognosis. In this context, targeted multimodal molecular imaging, the combination of different imaging modalities overcoming their individual limitations, has attracted great attention. Due to their unique properties, advanced nanomaterials have taken center stage in the development of theranostics.

An Electrochemical Enzyme Biosensor for 3-Hydroxybutyrate Detection Using Screen-Printed Electrodes Modified by Reduced Graphene Oxide and Thionine.

A biosensor for 3-hydroxybutyrate (3-HB) involving immobilization of the enzyme 3-hydroxybutyrate dehydrogenase onto a screen-printed carbon electrode modified with reduced graphene oxide (GO) and thionine (THI) is reported here. After addition of 3-hydroxybutyrate or the sample in the presence of NAD⁺ cofactor, the generated NADH could be detected amperometrically at 0.0 V vs.

Molecular Biosensors for Electrochemical Detection of Infectious Pathogens in Liquid Biopsies: Current Trends and Challenges.

Rapid and reliable diagnosis of infectious diseases caused by pathogens, and timely initiation of appropriate treatment are critical determinants to promote optimal clinical outcomes and general public health. Conventional in vitro diagnostics for infectious diseases are time-consuming and require centralized laboratories, experienced personnel and bulky equipment. Recent advances in electrochemical affinity biosensors have demonstrated to surpass conventional standards in regards to time, simplicity, accuracy and cost in this field.

Non-Invasive Breast Cancer Diagnosis through Electrochemical Biosensing at Different Molecular Levels.

The rapid and accurate determination of specific circulating biomarkers at different molecular levels with non- or minimally invasive methods constitutes a major challenge to improve the breast cancer outcomes and life quality of patients. In this field, electrochemical biosensors have demonstrated to be promising alternatives against more complex conventional strategies to perform fast, accurate and on-site determination of circulating biomarkers at low concentrations in minimally treated body fluids. In this article, after discussing briefly the relevance and current challenges associated with the determination of breast cancer circulating biomarkers, an updated overview of the electrochemical affinity biosensing strategies emerged in the last 5 years for this purpose is provided highlighting the great potentiality of these methodologies.

Electrochemical Genosensing of Circulating Biomarkers.

Management and prognosis of diseases requires the measurement in non- or minimally invasively collected samples of specific circulating biomarkers, consisting of any measurable or observable factors in patients that indicate normal or disease-related biological processes or responses to therapy. Therefore, on-site, fast and accurate determination of these low abundance circulating biomarkers in scarcely treated body fluids is of great interest for health monitoring and biological applications. In this field, electrochemical DNA sensors (or genosensors) have demonstrated to be interesting alternatives to more complex conventional strategies.

Rapid Legionella pneumophila determination based on a disposable core-shell Fe₃O₄@poly(dopamine) magnetic nanoparticles immunoplatform.

A novel amperometric magnetoimmunoassay, based on the use of core-shell magnetic nanoparticles and screen-printed carbon electrodes, was developed for the selective determination of Legionella pneumophila SG1. A specific capture antibody (Ab) was linked to the poly(dopamine)-modified magnetic nanoparticles (MNPs@pDA-Ab) and incubated with bacteria. The captured bacteria were sandwiched using the antibody labeled with horseradish peroxidase (Ab-HRP), and the resulting MNPs@pDA-Ab-Legionella neumophila-Ab-HRP were captured by a magnetic field on the electrode surface.

Clinical evaluation of a disposable amperometric magneto-genosensor for the detection and identification of Streptococcus pneumoniae.

A disposable PCR-based amperometric magneto-genosensor for detection and identification of Streptococcus pneumoniae was evaluated. ROC curve analysis used to determine optimal signal cutoff values yielded a sensitivity of 91% and a specificity of 90%. The method was also tested for the direct detection of pneumococci in clinical samples.

Preparation of core-shell FeO@poly(dopamine) magnetic nanoparticles for biosensor construction.

Novel core-shell FeO@poly(dopamine) magnetic nanoparticles were prepared through an in situ self-polymerization method. The hybrid nanomaterial showed an average core diameter of 11 ± 3 nm and a polymer thin film thickness of 1.8 ± 0.

Unravelling the gallic acid degradation pathway in bacteria: the gal cluster from Pseudomonas putida.

Gallic acid (3,4,5-trihydroxybenzoic acid, GA) is widely distributed in nature, being a major phenolic pollutant and a commonly used antioxidant and building-block for drug development. We have characterized the first complete cluster (gal genes) responsible for growth in GA in a derivative of the model bacterium Pseudomonas putida KT2440. GalT mediates specific GA uptake and chemotaxis, and highlights the critical role of GA transport in bacterial adaptation to GA consumption.

Disposable amperometric magnetoimmunosensors for the specific detection of Streptococcus pneumoniae.

Disposable amperometric magnetoimmunosensors, based on the use of functionalized magnetic beads and gold screen-printed electrodes, have been developed for the selective detection and quantification of Streptococcus pneumoniae. A specific antibody prepared against a serotype 37 S. pneumoniae strain, selected by flow cytometry among seven anticapsular or antisomatic antibodies, was linked to Protein A-modified magnetic beads and incubated with bacteria.

An electrochemical method for simultaneous detection and identification of Escherichia coli, Staphylococcus aureus and Salmonella choleraesuis using a glucose oxidase-peroxidase composite biosensor.

Quantification of bacterial pollution by amperometric detection at 0.0 V of glucose consumption at a graphite-Teflon-glucose oxidase-peroxidase-ferrocene composite biosensor under flow injection conditions is reported. Using Escherichia coli as the model bacterium, the composition of the growing medium was optimized.